Frequent users to ChemSpider who use the identifiers for searching will commonly find a mixture of “names” and “database IDs” as well as “registry numbers”. Since the number of database IDs can sometimes swamp the synonyms and chemical names we chose to separate them. We have run some regular expressions across the database to separate database IDs out. We have left registry numbers (marked by [RN]), EINECS numbers (marked by [EINECS]) and Wiswesser Line Notation (marked by [WLN]) in with the synonyms.

Unfortunately there are MANY flavors of Database IDs and we might have missed some. If you come across any “potential” DB IDs and think we should segregate them out please use the POST COMMENTS ability to inform us. Simply Post a Comment to a record and suggest we check the identifiers out for potential DBIDs. Thank!